feat: enhance PlateEditor with MDX expression escaping and add remarkMdx support for improved markdown parsing

surfsense_web/components/editor/utils/escape-mdx.ts

@@ -0,0 +1,26 @@
+// ---------------------------------------------------------------------------
+// MDX curly-brace escaping helper
+// ---------------------------------------------------------------------------
+// remarkMdx treats { } as JSX expression delimiters. Arbitrary markdown
+// (e.g. AI-generated reports) can contain curly braces that are NOT valid JS
+// expressions, which makes acorn throw "Could not parse expression".
+// We escape unescaped { and } *outside* of fenced code blocks and inline code
+// so remarkMdx treats them as literal characters while still parsing
+// <mark>, <u>, <kbd>, etc. tags correctly.
+// ---------------------------------------------------------------------------
+
+const FENCED_OR_INLINE_CODE = /(```[\s\S]*?```|`[^`\n]+`)/g;
+
+export function escapeMdxExpressions(md: string): string {
+  const parts = md.split(FENCED_OR_INLINE_CODE);
+
+  return parts
+    .map((part, i) => {
+      // Odd indices are code blocks / inline code – leave untouched
+      if (i % 2 === 1) return part;
+      // Escape { and } that are NOT already escaped (no preceding \)
+      return part.replace(/(?<!\\)\{/g, '\\{').replace(/(?<!\\)\}/g, '\\}');
+    })
+    .join('');
+}
+